Nokia Maps Suite 2.0 and Maps 3.09 install the Check in application only in China. In the other regions Check in is not installed as part of the Nokia Maps Suite 2.0 bundle.
If updating from Maps 3.08 to Maps 3.09, the Check in application that came with Maps 3.08 is preserved. Check in can be used normally after the update. However, if updating from Maps 3.06 to Maps 3.09, the Check in feature is not any more available after the update. Also when the phone is initially shipping with Maps 3.09, there is no Check in application.
Note that if resetting the device with the Delete data and restore command, the Check in application will be removed and cannot be restored by installing Maps Suite 2.0 and Maps 3.09.